JP2002044130A - Multicast communication method and communication device - Google Patents

Abstract

(57) [Summary] An IP multicast communication is performed between an IPv4 terminal and an IPv6 terminal. For example, a conversion device 1 associates an IP transmission / reception unit 2 for transmitting / receiving an IP packet, a conversion IP address holding unit 3 for holding an IP address used for IP header conversion, and addresses of IPv4 and IPv6. IP address conversion information holding means 4 for holding IPv4 and IPv4
IP header conversion means 5 for performing Pv6 IP header conversion
And an IP multicast routing control information management unit 6 for converting the IPv4 and IPv6 IP multicast routing control information to each other to perform route control, and an IP multicast membership information management unit 7 for managing IP multicast members.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicast communication method and a communication apparatus, and more particularly, to an IPv4 (IPv4: Internet Protocol version) as a communication protocol.
4) and IPv6 (IPv6: Internet Protocol version) as a communication protocol.
The present invention relates to a multicast communication method and a communication device for performing multicast communication between IPv6 terminals using 6).

[0002]

2. Description of the Related Art In recent years, as the number of hosts connected to the Internet has rapidly increased, it is expected that the address space will be exhausted only with IPv4 (Internet Protocol version 4) having a 32-bit address space. To avoid this depletion of address space, IPv4
The next version of IPv4, IPv6, has been developed and is attracting attention as a means for networking new terminals (for example, mobile IP terminals).

[0003] An IPv4 terminal using this IPv4 and I
As a method for realizing communication between IPv6 terminals using Pv6, for example, a technique described in Japanese Patent Application Laid-Open No. 10-136052 can be mentioned. This Japanese Patent Application Laid-open No. Hei 10-13
Japanese Patent No. 6052 discloses that the D
NS protocol extension technology (DNS: Domain Name System)
m), an IP address translation table for managing the correspondence between the IPv4 address and the IPv6 address is created, and based on the IP address translation table,
4 header-IPv6 header conversion is performed. This allows I
Communication between the Pv4 terminal and the IPv6 terminal can be performed.

[0004]

However, according to the above-mentioned technique, IP unicast communication between an IPv4 terminal and an IPv6 terminal can be performed, but IP multicast communication cannot be performed. Here, the unicast refers to one-to-one communication, and the multicast refers to one-to-many specific communication (communication within a specific group).

[0005] In view of the above points, the present invention converts an IP multicast packet broadcast from an IPv4 terminal into an IPv4 packet.
An object of the present invention is to provide a multicast communication method and a communication device in which an IPv4 terminal receives an IP multicast packet broadcasted from an IPv6 terminal while being received by six terminals.

[0006]

According to a first aspect of the present invention, there is provided a multicast communication method between an IPv4 network including an IPv4 terminal and an IPv6 network including an IPv6 terminal, the method comprising: IP with fixed data added to IPv4 address of a certain group of multicast packets
When a request to join the group with the IPv6 address is received from the IPv6 terminal, the IPv6 address of the group is reflected in the management information of the IP multicast group membership protocol, and the IPv6 address of the group is reflected.
6 addresses and the IPv4 addresses of the group, and as a relay request for the IPv4 addresses of the group, the information is reflected in the management information of the IP multicast routing protocol, and the IPv4 terminal broadcasts the IPv4 address.
4 receives the multicast packet, the IPv4
IP of the group contained in the multicast packet
v4 destination address to the corresponding IPv6 of the group
It converts to the end point address and a predetermined IPv4 address.
6 unicast address, and set the IPv4 source address contained in the IPv4 multicast packet to I
By converting to a Pv6 start address, the IPv6
The present invention provides a multicast communication method in which an IPv6 multicast packet is created from four multicast packets, and the created IPv6 multicast packet is transmitted to an IPv6 network.

As a result, the IP of the IPv4 network is
v4 terminal broadcasts the IP multicast packet
It can be received by the IPv6 terminal of the Pv6 network. At this time, the processes performed by the conversion device between the IPv4 terminal and the IPv6 terminal are all technologies described in RFC, and there is no need to make new changes to the IPv4 terminal and the IPv6 terminal.

[0008] According to a second solution of the present invention, the IPv4
A multicast communication method between an IPv4 network including four terminals and an IPv6 network including an IPv6 terminal, wherein the fixed data is deleted from an IPv6 address of a group of an IPv6 multicast packet broadcasted by the IPv6 terminal. When a request to join a group is received from an IPv4 terminal, the IPv4 address of the group is reflected in management information of an IP multicast group membership protocol, and the IPv4 address of the group is associated with the IPv6 address of the group. , As a relay request for the IPv6 address of the group,
When the IPv6 terminal receives an IPv6 multicast packet broadcast by the IPv6 terminal, the IPv6 terminal converts the IPv6 destination address of the group included in the IPv6 multicast packet into a corresponding IPv4 destination address of the group, which is reflected in the management information of the multicast routing protocol. In addition, an IPv4 multicast packet is created from the IPv6 multicast packet by selecting a predetermined IPv4 unicast address and converting an IPv6 source address included in the IPv6 multicast packet into an IPv4 source address. Provided is a multicast communication method for transmitting an IPv4 multicast packet to an IPv4 network.

As a result, the IP address of the IPv6 network
v6 terminals broadcast IP multicast packets
It can be received by the IPv4 terminal of the v4 network. At this time, the processes performed by the conversion device between the IPv4 terminal and the IPv6 terminal are all technologies described in RFC, and there is no need to make new changes to the IPv4 terminal and the IPv6 terminal.

[0010] According to a third solution of the present invention, the IPv4
A multicast communication device in a communication network system, provided between a IPv4 network including four terminals and an IPv6 network including IPv6 terminals, and having a conversion device for transmitting and receiving IP packets,
An IP transmitting / receiving unit for transmitting / receiving packets, a conversion IP address holding unit for holding an IP address used for IP header conversion, an IP address conversion information holding unit for holding IPv4 and IPv6 addresses in association with each other,
Header conversion means for performing IP header conversion of IPv6 and IPv6, and IP multicast routing control information relating to an IP network to which an IP multicast packet broadcast from an IPv4 and IPv6 IP multicast server is to be relayed, and performing routing control. An IP multicast routing control information managing unit; and an IP multicast membership information managing unit for managing an IP multicast member, wherein the IP header converting unit is configured to control an IP of the IPv4 multicast packet passed from the IP transmitting / receiving unit.
The IPv4 destination address is inquired to the IP address translation information holding means to convert the IPv4 destination address into the IPv6 destination address using the corresponding IPv6 address, and the IPv4 source address of the IPv4 multicast packet is converted into the I4 address.
An IPv6 multicast packet is created from an IPv4 multicast packet by an IP header conversion for inquiring a P address conversion information holding unit and converting the IPv6 source address to an IPv6 start address using a corresponding IPv6 address, and sending to the IPv6 network is performed by the IP transmitting / receiving unit. , And the IP passed from the IP transmitting / receiving means.
The IPv6 end point address of the Pv6 multicast packet is inquired to the IP address translation information holding unit to convert the IPv6 end point address of the IPv6 multicast packet to the IPv4 end address using the corresponding IPv4 address. Multicast communication that creates an IPv4 multicast packet from an IPv6 multicast packet and instructs an IP transmitting / receiving unit to send the packet to an IPv4 network by performing an IP header conversion that inquires and converts the IPv4 address to an IPv4 start address using a corresponding IPv4 address. Provide equipment. In a first perspective,
The present invention provides a method of performing IP multicast communication between an IPv4 terminal of an IPv4 network and an IPv6 terminal of an IPv6 network in a communication network system including an IPv4 network, an IPv6 network, and a conversion device connected to both of them. ) The conversion device has an RFC 2236 (RFC: Request for
Comments) and IP described in RFC2710, etc.
According to the multicast group membership protocol and the IP multicast routing control protocol described in RFC2362, draft-ietf-pim-v2-dm-03.txt, etc., it operates as an IPv4 multicast router in an IPv4 network, and operates as an IPv4 multicast router in an IPv6 network. Operating as an IPv6 multicast router, (b)
The fixed data (I) is added to the IPv4 address of the group of the IPv4 multicast packet broadcast by the IPv4 terminal.
A request to join an IPv6 address group that can be created by adding a Pv6 multicast prefix
6 terminal, the IPv6 address of the group is reflected in the management information of the IP multicast group membership protocol, and the IPv6 address of the group is
6 addresses and the IPv4 addresses of the group, and further, as a relay request for the IPv4 addresses of the group, is reflected in management information of the IP multicast routing protocol, and exchanges IP multicast routing information with an adjacent IPv4 multicast router,
(C) The conversion device transmits the I broadcast by the IPv4 terminal.
When a Pv4 multicast packet is received, the IP
An IPv4 destination address included in a v4 multicast packet is converted to an IP address using the corresponding IPv6 address.
v6 destination address and the IP address previously stored in the conversion device according to the instruction of the administrator.
An IPv6 multicast packet is created from the IPv4 multicast packet by an IP header translation that selects one of the v6 unicast addresses and translates the IPv4 source address contained in the IPv4 multicast packet into an IPv6 source address using the unicast address. To the IPv6 network, and (d) the IPv6
The six terminals provide an IPv4-IPv6 multicast communication method, wherein the terminal receives the IPv6 multicast packet.

In a second aspect, the present invention provides a communication network system comprising an IPv4 network, an IPv6 network, and a conversion device connected to both of them.
A method for performing IP multicast communication with an IPv6 terminal of a network, comprising:
IP multicast group membership protocol and RFC described in H.236, RFC2710, etc.
According to the IP multicast routing protocol described in 2362 and draft-ietf-pim-v2-dm-03.txt, etc., it operates as an IPv4 multicast router in an IPv4 network, and operates as an IPv4 multicast router in an IPv6 network.
v6 multicast router, and (b) the I
From the IPv6 address of the group of the IPv6 multicast packet broadcast by the Pv6 terminal, fixed data (IPv6
6 Multicast prefix) IP
When a request to join the group of the v4 address is received from the IPv4 terminal, the IPv4 address of the group is reflected in the management information of the IP multicast group membership protocol, and the IPv4 address of the group is associated with the IPv6 address of the group. ,
Further, the control information is reflected in the management information of the IP multicast routing protocol as a relay request for the IPv6 address of the group, and the IP multicast routing control information is exchanged with an adjacent IPv6 multicast router. When receiving the IPv6 multicast packet, the IPv6 destination address included in the IPv6 multicast packet is converted into an IPv4 destination address using the corresponding IPv4 address, and is stored in the conversion device in advance according to the instruction of the administrator. Select one of the existing IPv4 unicast addresses and use
An IPv4 multicast packet is created from the IPv6 multicast packet by performing an IP header conversion for converting an IPv6 start address included in the IPv6 multicast packet into a Pv4 start address,
(v) sending the packet to a v4 network, wherein the IPv4 terminal receives the IPv4 multicast packet.

In a third aspect, the present invention relates to a communication network system including an IPv4 network, an IPv6 network, and a conversion device connected to both of them.
A method for performing IP multicast communication with an IPv6 terminal of a network, comprising:
IP multicast group membership protocol and RFC described in H.236, RFC2710, etc.
According to the IP multicast routing protocol described in 2362 and draft-ietf-pim-v2-dm-03.txt, etc., it operates as an IPv4 multicast router in an IPv4 network, and operates as an IPv4 multicast router in an IPv6 network.
v6 multicast router, and (b) the I
Fixed data (IPv6) is stored in the IPv4 address of the group of the IPv4 multicast packet broadcast by the Pv4 terminal.
IPv4 that can be created by adding a multicast prefix)
IP requesting relay of packet of 6 address group
When receiving the multicast routing control information from an adjacent IPv6 multicast router, the
associating a v6 address with the IPv4 address of the group, further reflecting the information in the management information of the IP multicast routing protocol as a relay request for the IPv4 address of the group, and exchanging IP multicast routing information with an adjacent IPv4 multicast router;
(C) The conversion device transmits the I broadcast by the IPv4 terminal.
When a Pv4 multicast packet is received, the IP
An IPv4 destination address included in a v4 multicast packet is converted to an IP address using the corresponding IPv6 address.
v6 destination address and the IP address previously stored in the conversion device according to the instruction of the administrator.
An IPv6 multicast packet is created from the IPv4 multicast packet by an IP header translation that selects one of the v6 unicast addresses and translates the IPv4 source address contained in the IPv4 multicast packet into an IPv6 source address using the unicast address. To the IPv6 network, and (d) the IPv6
The six terminals provide an IPv4-IPv6 multicast communication method, wherein the terminal receives the IPv6 multicast packet.

Thus, the IP of the IPv4 network is
v4 terminal broadcasts IP multicast packets
It can be received by the IPv6 terminal of the v6 network. At this time, the conversion device is configured to transmit the IPv4 terminal and the IPv4
The processing performed with the six terminals is all a technique described in RFC, and there is no need to add a new modification to the IPv4 terminal and the IPv6 terminal.

According to a fourth aspect, the present invention provides a communication network system comprising an IPv4 network, an IPv6 network, and a conversion device connected to both the IPv4 network and the IPv6 network.
A method for performing IP multicast communication with an IPv6 terminal of a network, comprising:
IP multicast group membership protocol and RFC described in H.236, RFC2710, etc.
According to the IP multicast routing protocol described in 2362 and draft-ietf-pim-v2-dm-03.txt, etc., it operates as an IPv4 multicast router in an IPv4 network, and operates as an IPv4 multicast router in an IPv6 network.
v6 multicast router, and (b) the I
From the IPv6 address of the group of the IPv6 multicast packet broadcast by the Pv6 terminal, fixed data (IPv6
6 Multicast prefix) IP
I requesting the relay of the packet of the group of the v4 address
When P multicast routing control information is received from an adjacent IPv4 multicast router,
Associating the Pv4 address with the IPv6 address of the group, further reflecting the information in the management information of the IP multicast routing protocol as a relay request for the IPv6 address of the group, exchanging the IP multicast routing information with an adjacent IPv6 multicast router,
(C) The conversion device transmits the I broadcast by the IPv6 terminal.
When a Pv6 multicast packet is received, the IP
An IPv6 destination address included in a v6 multicast packet is converted to an IP address using the corresponding IPv4 address.
v4 destination address and the IP stored in the conversion device in advance according to the instruction of the administrator.
An IPv4 multicast packet is created from the IPv6 multicast packet by an IP header translation that selects one of the v4 unicast addresses and translates the IPv6 source address contained in the IPv6 multicast packet into an IPv4 source address using the selected unicast address. To the IPv4 network, and (d) the IPv4
The four terminals provide an IPv4-IPv6 multicast communication method, wherein the four terminals receive the IPv4 multicast packet.

[0015] Thereby, the IP of the IPv6 network is
v6 terminals broadcast IP multicast packets
It can be received by the IPv4 terminal of the v4 network. At this time, the conversion device is configured to transmit the IPv4 terminal and the IPv4
The processing performed with the six terminals is all a technique described in RFC, and there is no need to add a new modification to the IPv4 terminal and the IPv6 terminal.

[0016] In a fifth aspect, the present invention provides:
IP transmitting / receiving means for transmitting / receiving and relaying an IPv4 packet to / from an IPv4 network, transmitting / receiving and relaying an IPv6 packet to / from an IPv6 network, and (b) IPv4 unicast address and I used for IP header conversion
A conversion IP address holding unit for holding a Pv6 unicast address; and (c) an IP address of the IPv4 network.
An IPv4 multicast address broadcast by a Pv4 terminal, an IPv4 end address of the IPv4 multicast packet, an IPv6 multicast address obtained by adding fixed data (IPv6 multicast prefix) to the IPv4 end address, an IPv4 start address of the IPv4 multicast packet, and holding of the conversion IP address. IP obtained from the means
v6 unicast address (obtain if not completed),
I broadcast by an IPv6 terminal of the IPv6 network
From the IPv6 destination address of the Pv6 multicast packet and the IPv6 destination address, fixed data (IPv6
IPv4 created by removing multicast prefix)
IP address translation information holding means for holding the IPv4 multicast address, the IPv6 start address of the IPv6 multicast packet, and the IPv4 unicast address acquired from the translation IP address holding means (acquired if not yet completed), and , (D) RFC
2362 and draft-ietf-pim-v2-dm-03.txt to manage IP multicast routing control information in accordance with the IP multicast routing control protocol.
From the IPv6 address of the group of the IPv6 multicast packet broadcast by the Pv6 terminal, fixed data (IPv6
6 Multicast prefix) IP
I requesting the relay of the packet of the group of the v4 address
When the P multicast routing control information is received from an adjacent IPv4 multicast router, the IPv4 address of the IPv4 multicast group and the IPv4
An IPv6 address that can be obtained by adding fixed data (IPv6 multicast prefix) to the address
The address translation information holding means is instructed to register, and the request is reflected in the management information of the IP multicast routing protocol as a relay request for the IPv6 address of the group.
Exchange multicast routing information, and
IPv6 formed by adding fixed data (IPv6 multicast prefix) to an IPv4 address of a group of IPv4 multicast packets broadcast by a v4 terminal
When receiving the IP multicast routing control information requesting the relay of the packet of the group of addresses from the adjacent IPv6 multicast router, the IPv6 address of the IPv6 multicast group and the fixed data (IPv6 multicast prefix) are deleted from the IPv6 address. A possible IPv4 address is instructed and registered in the IP address conversion information holding means, and further reflected as a relay request for the IPv4 address of the group in the management information of the IP multicast routing protocol, so that the adjacent IPv4 multicast router and the IP multicast routing control IP multicast routing control information management means for exchanging information, and (e) an IP multicast group membership protocol described in RFC2236 or the like. Accordingly, when managing the members of the IPv4 multicast group and receiving the request to join the IPv4 multicast group transmitted from the IPv4 terminal in the connected IPv4 network, the request is reflected on the management information of the IP multicast group membership protocol, and I of IPv4 multicast group
An IP multicast for requesting the IP address translation information holding means to register a Pv4 address and an IPv6 address obtained by adding fixed data (IPv6 multicast prefix) to the IPv4 address, and further requesting the relay of the packet of the IPv6 address. Instructs the IP multicast routing control information managing means to register the routing control information, and also manages and connects the members of the IPv6 multicast group according to the IP multicast group membership protocol described in RFC2710 or the like. When a request to join an IPv6 multicast group transmitted from an IPv6 terminal within the server is received, the request is reflected in management information of an IP multicast group membership protocol, and the IP 6 of the multicast group IP
An IP multicast that instructs the IP address translation information holding unit to register an IPv4 address obtained by deleting fixed data (IPv6 multicast prefix) from the IPv6 address and the IPv6 address, and further requests the relay of the packet of the IPv4 address. IP multicast membership information management means for instructing the IP multicast routing control information management means to register routing control information, and (f) converting the IPv4 end address of an IPv4 multicast packet passed from the IP transmitting / receiving means to the IP address conversion. Inquiry to the information holding means, the IPv6 address using the corresponding IPv6 address
6 IPv6 destination address and the IPv4 source address of the IPv4 multicast packet
An IPv6 multicast packet is created from the IPv4 multicast packet by an IP header translation that inquires a P address translation information holding unit and translates the IPv6 address into an IPv6 source address using the corresponding IPv6 address, and sends the IPv6 multicast packet to an IPv6 network. I / O of the IPv6 multicast packet instructed to the transmitting / receiving means and similarly passed from the IP transmitting / receiving means
The IPv6 destination address is inquired to the IP address translation information holding means to convert it to an IPv4 destination address using the corresponding IPv4 address, and the IPv6 source address of the IPv6 multicast packet is sent to the IP address translation information holding means. Inquiry, IPv4 address using the corresponding IPv4 address
And an IP header conversion unit for generating an IPv4 multicast packet from the IPv6 multicast packet by IP header conversion for converting the IP address into a 4-source address, and further instructing the IP transmitting / receiving unit to send the packet to an IPv4 network. A conversion device is provided.

According to the present invention, an IPv6 terminal can receive an IP multicast packet broadcast from an IPv4 terminal. Further, according to the present invention, an IP multicast packet broadcast from an IPv6
Can be received by the terminal.

Another feature of the present invention is that
The P address translation information holding unit stores the IPv4
Of the unicast address and the IPv6 unicast address, those that have not been referenced for a certain period of time may be deleted and returned to the conversion IP address holding means. As a result, the unused IPv4 unicast address or IPv6 unicast address is returned to the conversion IP address holding unit, so that the consumption of the IPv4 unicast address or the IPv6 unicast address can be suppressed.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. (First Embodiment) FIG. 1 is a configuration diagram of a first embodiment of a conversion apparatus 1 according to the present invention. The conversion device 1
Mainly, IPv4 networks 111 and 112 and IPv6
It is located between the networks 121 and 122, and
By converting the IP header of the Pv4 multicast packet and the IPv6 multicast packet, the IPv4 terminal and the I
An apparatus for performing IP multicast communication between Pv6 terminals, for example, an IP transmission / reception unit 2 including an electronic device such as a CPU, an ASIC, and a RAM, a conversion IP address holding unit 3, an IP address conversion information holding unit 4, It comprises an IP header conversion means 5, an IP multicast routing control information management means 6, an IP multicast membership information management means 7, and interfaces 8 to 11. In addition,
The interfaces 8 to 11 are connected to the IP transmitting / receiving means 2 and the
It is a point connecting the four networks 111 and 112 and the IPv6 networks 121 and 122.

The IP transmitting / receiving means 2 transmits / receives and relays an IPv4 packet to / from the IPv4 networks 111 and 112, and transmits / receives an IPv6 packet to / from the IPv6 networks 121 and 122.
It transmits and receives packets and relays them. The conversion IP address holding unit 3 uses an IP address conversion unit
Holds a Pv4 unicast address and an IPv6 unicast address. IP used for this IP header conversion
The v4 unicast address and the IPv6 unicast address are determined in advance by the administrator (or maintenance person, etc.) of the conversion device 1.
And are stored in an IPv4 unicast address table 31 and an IPv6 unicast address table 32, respectively, which will be described later.

FIG. 2 is a configuration diagram of the IPv4 unicast address table 31. The IPv4 unicast address table 31 contains an IPv4 address used for the IP header conversion.
4 unicast addresses are registered in advance in accordance with, for example, an instruction from the administrator. Here, the IPv4 addresses (here, as an example, 133.144.94.
100-133.144.94.200. Hereinafter, an example is similarly shown in parentheses. ) Is registered.

FIG. 3 is a configuration diagram of the IPv6 unicast address table 32. The IPv6 unicast address table 32 includes an IPv6 address used for the IP header conversion.
For example, six unicast addresses are registered in advance according to an instruction of the administrator, and here, IPv6 addresses (4 :: 100 to 4 :: 200) are registered.

The IP address conversion information holding means 4
Has an IP address conversion table. The IP address conversion information holding unit 4 is configured to transmit the IPv4
IPv4 destination address of 4 multicast packets;
I that can be obtained by adding fixed data (IPv6 multicast prefix) to the IPv4 destination address
A Pv6 multicast address, an IPv4 start address of an IPv4 multicast packet, an IPv6 unicast address obtained from the conversion IP address holding means 3 (if not already obtained), and an IPv6 end address of an IPv6 multicast packet broadcast by an IPv6 terminal. And fixed data (I
IPv4 multicast address that can be obtained by deleting Pv6 multicast prefix) and IPv4
6 IPv6 source address of the multicast packet;
The IPv4 unicast address acquired from the conversion IP address holding unit 3 (acquired if not yet acquired) is held in association with each other. The IP address conversion information holding unit 4 is configured by an electronic device such as a CPU, an ASIC, and a RAM.

FIG. 4 is a configuration diagram of the IP address conversion table 41. The IP address conversion table 41 stores, for example, the I
Pv4 end address and its corresponding IPv6 address (item 1), received IPv4 multicast packet's IPv4 start address and its corresponding IPv6 address (item 2), received IPv6 multicast packet's IPv6 end address and its corresponding IPv4 The address (item number 3), the IPv6 start address of the received IPv6 multicast packet, and the corresponding IPv4 address (item number 4) are held in association with each other.

The IP header conversion means 5 receives the IPv4 multicast packet transmitted from the IP transmission / reception means 2 and performs an IP header conversion to create an IPv6 multicast packet.
Send to Specifically, the IP header conversion is performed by using the IPv4
The IPv4 destination address of the multicast packet is represented by I
By inquiring of the P address conversion information holding means 4, it is converted to an IPv6 end address using the IPv6 address corresponding to the IPv4 end address, and similarly, the IPv4
By inquiring the IP address conversion information holding means 4 of the four start addresses, the four start addresses are converted into IPv6 start addresses using the IPv6 addresses corresponding to the IPv4 start addresses.

The IP header conversion means 5 receives the IPv6 multicast packet transmitted from the IP transmission / reception means 2 and performs IP header conversion to obtain an IPv6 multicast packet.
4) Create a multicast packet and transmit it to the IP transmitting / receiving means 2 again. The IP header conversion is, specifically,
By inquiring the IPv6 destination address of the Pv6 multicast packet to the IP address translation information holding means 4, the IPv6 address corresponding to the IPv6 end address is obtained.
Using the four addresses to convert to an IPv4 destination address,
Further, similarly, the IPv6 multicast packet I
By inquiring the IPv6 start address to the IP address conversion information holding unit 4, the Pv6 start address is converted to an IPv4 start address using the IPv4 address corresponding to the IPv6 start address. The IP header conversion means 5 is composed of an electronic device such as a CPU, an ASIC, and a RAM, for example.

The IP multicast routing control information management means 6 manages the IP multicast routing control information based on the IPv4 multicast routing control information and the IPv6 multicast routing control information described later.
The relay destination of the Pv4 multicast packet and the IPv6 multicast packet is determined. The IPv4 multicast routing control information is exchanged and collected with an adjacent IPv4 multicast router, for example, according to the IP multicast routing protocol, and also takes into account the IPv4 multicast group member information notified from the IP multicast membership information managing unit 7. Obtained by: Similarly, the IPv6 multicast routing control information is exchanged, collected, and managed with, for example, an adjacent IPv6 multicast router.
It is obtained by taking into account the IPv6 multicast group member information notified from the multicast membership information management means 7. The IP multicast path control information management means 6 is configured by an electronic device such as a CPU, an ASIC, and a RAM. The IPv4 multicast route control information and the IPv6 multicast route control information are held in the IP multicast route information table 51, respectively. IP multicast route information table 5
1 is stored in the IP multicast routing information management means 6 or in another appropriate memory.

FIG. 5 is a configuration diagram of the IP multicast route information table 51. The IP multicast route information table 51 holds information on an IP network to relay an IP multicast packet broadcast from an IP multicast server. The IPv4 multicast routing control information is a portion of the information held in the IP multicast routing information table 51 where IP multicast address = IPv4 multicast address. Further, the IPv6 multicast routing control information includes, among the information held in the IP multicast routing information table 51, IP multicast address = IP
This is the part that becomes the v6 multicast address.

FIG. 6 is a configuration diagram of the IPv4 adjacent router information table 71. The IPv4 adjacent router information table 71 holds information on an adjacent IPv4 multicast router. Here, as an entry for each item number, for example, in the item number “1”, the adjacent router information corresponding to the interface 8 is “OFF”, and in the item number “2”, the adjacent router information corresponding to the interface 9 Is "O
In the item number “3”, the adjacent router information corresponding to the interface 10 is “OFF”, and in the item number “4”, the adjacent router information corresponding to the interface 11 is “OFF”.

FIG. 7 is a configuration diagram of the IPv6 adjacent router information table 72. The IPv6 adjacent router information table 72 holds information on adjacent IPv6 multicast routers. Here, as an entry for each item number, for example, in the item number “1”, the adjacent router information corresponding to the interface 8 is “OFF”, and in the item number “2”, the adjacent router information corresponding to the interface 9 Is "O
In the item number “3”, the adjacent router information corresponding to the interface 10 is “OFF”, and in the item number “4”, the adjacent router information corresponding to the interface 11 is “OFF”.

[0031] The IP multicast membership information management means 7 uses the IPv4 described in RFC2236 or the like.
According to the multicast group membership protocol, a request for joining or leaving an IPv4 multicast group transmitted from an IPv4 terminal is received, and IPv4 multicast group member information in a directly connected IPv4 network is collected and managed. The IPv4 multicast group member information is
Notify the P multicast route control information management means 6.

Further, the IP multicast membership information management means 7 transmits an IPv6 signal transmitted from an IPv6 terminal according to an IPv6 multicast group membership protocol described in RFC2710 or the like.
Receiving a request to join or leave a multicast group and receiving IP requests in a directly connected IPv6 network
It collects and manages v6 multicast group member information, and notifies the IPv6 multicast group member information to the IP multicast routing control information management means 6. Here, RFC 2362 and draft-ietf-pim-v2-
PIM (Protocol Indepe) described in dm-03.txt etc.
ndent Multicast) Protocol Dense Mode (PIM-D
M protocol), but an appropriate protocol may be used.

The IPv4 multicast group member information is stored in the IPv4 multicast member information table 61.
In addition, IPv6 multicast group member information is IP
The v6 multicast member information table 62 holds the information.

FIG. 8 is a configuration diagram of the IPv4 multicast member information table 61. The IPv4 multicast member information table 61 includes an IPv4 terminal to which the IPv4 terminal subscribed to the IPv4 multicast address belongs.
4 network information is held. Here, IPv4
As an entry for each item number for four addresses (238.0.0.2), for example, in item number "1", the member enrollment information corresponding to the interface 8 is "OFF", and in item number "2", , The member enrollment information corresponding to the interface 9 is “ON”, the item enrollment information corresponding to the interface 10 is “OFF” in the item number “3”, and the item 11 “4” corresponds to the interface 11 in the item number “4”. The member enrollment information is “OFF”. Therefore, in this example, the IPv4 address (238.0.0.2) belongs to the interface 9.

FIG. 9 is a configuration diagram of the IPv6 multicast member information table 62. The IPv6 multicast member information table 62 includes an IPv6 terminal to which the IPv6 terminal subscribed to the IPv6 multicast address belongs.
6 network information is held. Here, IPv4
As an entry for each item number for the 6 addresses (ff1e :: 238.0.0.1), for example, in item number “1”, the member enrollment information corresponding to the interface 8 is “O”
In the item number “2”, the member enrollment information corresponding to the interface 9 is “OFF” and the item number “3”
In the item number “4”, the member enrollment information corresponding to the interface 10 is “OFF”.
The member enrollment information corresponding to No. 1 is “ON”. Therefore, in this example, IPv6 (ff1e :: 238.0.
0.1) belongs to the interface 11.

FIG. 10 is a configuration diagram of a communication network system 100 using the conversion device 1 according to the present invention.
In the communication network system 100, for example, the conversion device 1 (here, as an example, an IPv4 address;
133.144.93.1 and 133.144.95.
1, IPv6 addresses; 1 :: 1 and 2: 1: are assigned. ) Via the IPv4 network 11
1 and 112 are connected to the IPv6 networks 121 and 122, and the IPv4 network 111
IPv4 multicast server 101 (IPv4 address; 13) that broadcasts multicast packets in Pv4
3.144.93.2), and the IPv4 network 112 includes an IPv4 multicast client 102 (I) that receives an IPv4 multicast packet.
Pv4 address; 133.144.95.2) is included. The IPv6 network 121 includes an IPv6 multicast server 103 (IPv6 address; 1 :: 2) for broadcasting a multicast packet in IPv6. , An IPv6 multicast client 104 (IPv6 address; 2 :: 2) that receives a multicast packet in IPv6.

The IPv4 multicast server 10
1 broadcasts an IPv4 multicast packet (IPv4 address; 238.0.0.1) to the IPv4 network 111, and
Is broadcasting an IPv6 multicast packet (IPv6 address; ff1e :: 238.0.0.2) to the IPv6 network 121, respectively.
Note that here, the IPv4 networks 111 and 112 are used.
And the IPv6 networks 121 and 122 are completely separated from each other, but the IPv4 networks 111 and 112
The same applies to a case where the IPv6 networks 121 and 122 are physically mixed in the same network.

Next, the communication network system 1
At 00, the IPv4 multicast server 101
Sends the IPv4 multicast packet (IPv4 address; 238.0.0.1) to the IPv4 network 1
And broadcasts the IPv4 multicast packet to the IPv6 multicast client 104.
Will be described.

First, the IGMP protocol (IGMP: In
The processing (processing 201 to 204) that the conversion device 1 performs periodically according to the Internet Group Management Protocol), the MLD protocol (MLD: Multicast Listener Discovery), and the PIM-DM protocol will be described. FIG. 12 is a communication sequence diagram for the processes 201 and 202.

(Process 201) The IP multicast membership information management means 7 creates an IGMP Query message according to the IGMP protocol, and instructs the IP transmission / reception means 2 to send the message to the IPv4 networks 111 and 112. IP transmission / reception means 2
Sends an IGMP Query message to the IPv4 networks 111 and 112. The IP transmitting / receiving means 2 transmits the IGMP Report message to the IPv4
When received from the network 111 or 112, the IGMP Report message is passed to the IP multicast membership information management means 7.

The IP multicast membership information management means 7 performs IGMP according to the IGMP protocol.
By analyzing the Report message, an IPv4 multicast member information table 61 is created (IPv4 address = Interface of member enrollment information of IPv4 multicast group address requesting to join by IGMP Report message = ON). However, here, since there is no subscriber of the IPv4 multicast group, the IP transmitting / receiving means 2 does not receive this IGMP Report message.

(Process 202) The IP multicast membership information management means 7 creates an MLD Query message according to the MLD protocol, and instructs the IP transmission / reception means 2 to send the message to the IPv6 networks 121 and 122. The IP transmitting / receiving means 2
LD Query message to IPv6 network 1
21 and 122. Also, the IP transmitting / receiving means 2
When receiving the MLD Report message from the IPv6 network 121 or 122, the MLD Report message
The report message is passed to the IP multicast membership information management means 7.

The IP multicast membership information management means 7 performs MLD Re-call according to the MLD protocol.
The port message is analyzed to create an IPv6 multicast member information table 62 (IPv6 address = interface of member enrollment information of IPv6 multicast group address requested to join by MLD Report message = ON). However, here, since there is no subscriber of the IPv6 multicast group, the IP transmitting / receiving means 2
Does not receive Report message. FIG. 13 is a communication sequence diagram for the processes 203 and 204.

(Regarding the process 203) The IP multicast routing information management means 6 creates a Hello message according to the PIM-DM protocol,
It instructs the IP transmission / reception means 2 to send to the IPv4 networks 111 and 112. The IP transmitting / receiving means 2
o message is sent to the IPv4 networks 111 and 112. When receiving the Hello message from the IPv4 network 111 or 112, the IP transmitting / receiving means 2 passes the Hello message to the IP multicast routing control information management means 6.

The IP multicast routing control information management means 6 performs Hello in accordance with the PIM-DM protocol.
The message is analyzed to create the IPv4 adjacent router information table 71 (adjacent router information of the interface that has received the Hello message is set to ON). However, here, since there is no IPv4 multicast router, the IP transmitting / receiving means 2
o Do not receive messages.

(Process 204) The IP multicast routing control information management means 6 creates a Hello message according to the PIM-DM protocol,
It instructs the IP transmission / reception means 2 to transmit to the IPv6 networks 121 and 122. The IP transmitting / receiving means 2
o message is sent to the IPv6 networks 121 and 122. Further, when receiving the Hello message from the IPv6 network 121 or 122, the IP transmission / reception unit 2 passes the Hello message to the IP multicast routing control information management unit 6.

The IP multicast routing control information management means 6 performs Hello based on the PIM-DM protocol.
The message is analyzed to create an IPv6 adjacent router information table 72 (adjacent router information of the interface that has received the Hello message is set to ON). However, here, since there is no IPv6 multicast router, the IP transmitting / receiving unit 2
o Do not receive messages.

Next, the communication network system 1
At 00, the IPv6 multicast client 10
4 is an IPv6 multicast group (ff1e :: 2
38.0.0.1) will be described. First, the processing in the conversion device 1 that has received an IPv4 multicast packet (addressed to 238.0.0.1) sent from the IPv4 multicast server 101 to the IPv4 network 111 will be described. FIG. 14 is a communication sequence diagram for the processes 205 to 207.

(Regarding process 205) IP transmitting / receiving means 2
Receives an IPv4 multicast packet (addressed to 238.0.0.1) from the IPv4 network 111, the IPv4 destination address of the IPv4 multicast packet (= IP multicast address = 238.0.
0.1) and an IPv4 start address (= IP multicast server address = 133.144.93.2) as a search key, a relay destination to which this IPv4 multicast packet should be relayed (IPv4 output information and IPv6 output information) IP multicast routing control information management means 6
Contact

(Step 206) The IP multicast route control information management means 6 inquires of the IP address conversion information holding means 4 about the IPv6 addresses corresponding to the IPv4 end address and the IPv4 start address, respectively.

(Regarding the process 207) First, the IP address conversion information holding means 4 checks that the IPv4 end address is
Check whether it is registered in the address conversion table 41,
It reports to the inquiry source (here, the IP multicast routing control information management means 6) whether the corresponding IPv6 address is registered or unregistered. If not registered, I
The Pv4 destination address is associated with an IPv6 address (ff1e :: 238.0.0.1) which is obtained by adding fixed data (IPv6 multicast prefix = for example, ff1e :: / 96) to the IPv4 destination address. Registered in the address translation table 41,
6 address (ff1e :: 238.0.0.1) to IP
This is reported to the multicast route control information management means 6.

The IP address conversion information holding means 4
Checks whether the IPv4 start address is registered in the IP address conversion table 41, and
It reports to the inquiry source (here, the IP multicast routing information management means 6) whether the 6 addresses are registered or unregistered. If the IPv6 unicast address has not been registered, an IPv6 unicast address is obtained from the conversion IP address holding unit 3 and registered in the IP address conversion table 41 in association with the IPv4 start address. Report to the management means 6. Here, since the IPv4 start address (133.144.93.2) is not registered in the IP address conversion table 41, the IPv6 unicast address (4 :: 100) is converted from the conversion IP address holding unit 3 to the IP address. After obtaining and registering it in the IP address conversion table 41, the IPv6 unicast address is reported. FIG. 15 shows the processes 208 and 209.
FIG. 4 is a communication sequence diagram for

(Step 208) Next, the IP multicast routing control information management means 6 sends the IPv4 end address (IP multicast address; 238.0.0.1) given from the IP transmission / reception means 2 to the IPv4 start address. (IP multicast server address; 13
3.144.93.2) is used as a search key to search the IP multicast route information table 51. If there is a corresponding entry in the IP multicast route information table 51, the output information (information indicating an interface and a protocol to be output) is notified to the IP transmitting / receiving means 2. On the other hand, if there is no corresponding entry, as described above,
IP multicast address (238.0.0.1),
IP multicast server address (133.144.
93.2) Create the respective entries.

Here, a description will be given of a set (setting) of the output information of the entry when notifying the IP transmitting / receiving means 2 of the output information of the entry of the IP multicast route information table 51 (information indicating the interface and protocol to be output). .

In the IPv4 adjacent router information table 71, the IPv4 output information of the interface for which the adjacent router information is set to ON is set to ON. The IPv6 output information of the interface whose neighboring router information is set to ON in the IPv6 neighboring router information table 72 is set to ON. The IPv4 output information of the interface whose IPv4 address is (238.0.0.1) in the IPv4 multicast member information table 61 and the interface of the member enrollment information is set to ON is set to ON. In the IPv6 multicast member information table 62, the IPv6 address is (ff1e :: 238.0.
0.1), the IPv6 output information of the interface whose member enrollment information interface is set to ON is set to ON. OF4 output information of the interface that received the IPv4 multicast packet
Set to F. In addition, IP that does not correspond to any of the above
The v4 output information and the IPv6 output information are set to OFF. Here, IPv4 output information of all interfaces = OFF, IPv6 output information of all interfaces =
The output information of OFF is notified from the IP multicast route control information management means 6 to the IP transmission / reception means 2.

(Regarding process 209) IP transmitting / receiving means 2
Indicates that an IPv4 network corresponding to an interface for which IPv4 output information = ON is
Send a v4 multicast packet. In this case, since the IPv4 output information of all interfaces is set to OFF, the IPv4 multicast packet is not transmitted to any IPv4 network. FIG. 16 is a communication sequence diagram for the processes 210 to 214.

(Regarding process 210) IP transmitting / receiving means 2
Passes the IPv4 multicast packet to the IP header conversion means 5.

(Regarding the process 211) The IP header conversion unit 5 inquires the IP address conversion information holding unit 4 of an IPv6 address corresponding to each of the IPv4 end address and the IPv4 start address of the IPv4 multicast packet.

(Regarding Step 212) The IP address conversion information holding means 4 executes the IP address conversion
An IPv6 address corresponding to each of the IPv4 end point address and the IPv4 start point address is acquired from the address conversion table 41, and reported to the inquiry source (here, the IP header conversion means 5).

(Process 213) The IP header conversion unit 5 converts the IPv6 address corresponding to the IPv4 end address into an IPv6 end address using the IPv6 address corresponding to the IPv4 end address, and also converts the IPv6 address into the IPv6 start address using the IPv6 address corresponding to the IPv4 start address. IP header conversion, IPv4 multicast packet to IP
v6 multicast packet is created, and the created I
The Pv6 multicast packet is returned to the IP transmitting / receiving means 2.

(Regarding process 214) IP transmitting / receiving means 2
Sends an IPv6 multicast packet to the IPv6 network corresponding to the interface set to IPv6 output information = ON notified from the IP multicast routing information management means 6 in (process 208). Here, IPv6 of all interfaces is used.
Since the output information is set to OFF, the IPv6 multicast packet is not transmitted to any IPv6 network.

Next, the IPv6 multicast client 104 sets the IPv6 multicast group (ff1
e :: 238.0.0.1) will be described. The IPv6 multicast client 104
Create an MLD Report message for joining the IPv6 multicast group (ff1e :: 238.0.0.1) according to the MLD protocol,
Send it to the IPv6 network 122. This MLD
The Report message is sent to the IPv6 network 12
2 will be described. FIG. 17 is a communication sequence diagram for the process 215.

(Regarding process 215) IP transmitting / receiving means 2
Passes the MLD message to the IP multicast membership information management means 7. The IP multicast membership information management means 7 analyzes the MLD message in accordance with the MLD protocol to create an IPv6 multicast member information table 62, and transmits the information obtained by analyzing the MLD message to the IP multicast path control information management means 6. Notify. The IP multicast route control information management means 6 creates the IP multicast route information table 51 according to the information obtained by analyzing the MLD message.

Here, by receiving the MLD message, the IPv6 multicast group (ff1
e :: 238.0.0.1) is found to be in the IPv6 network 122, so the interface 11 of the IPv6 address (ff1e :: 238.0.0.1) in the IPv6 multicast member information table 62. Is ON, IP multicast route information table 51
IPv6 address (ffle :: 238.0.0.
The interface 11 of 1) is set to ON. In the IP multicast route information table 51, the IPv6 address (ff1e :: 238.0.0.
In some cases, there are a plurality of entries of 1). In this case, the interface 11 of the plurality of entries is
Set to N.

Next, after (processing 215), the IPv4 multicast server 101
IPv4 multicast packet (23
The process performed by the conversion device 1 that has received the address “8.0.0.1” will be described. However, the processing of the conversion apparatus 1 after the processing 215 repeats the above-described processing 205 to 214 again. Details will be described below.

The IP transmission / reception means 2 performs (Process 205), and relays the IPv4 multicast packet
(v4 output information and IPv6 output information) to the IP multicast routing control information management means 6. The IP multicast routing control information management means 6 (process 206)
Is performed, and the IPv6 address corresponding to each of the IPv4 end point address and the IPv4 start point address is inquired to the IP address conversion information holding means 4.

The IP address conversion information holding means 4 performs (processing 207) to inquire the IPv6 address corresponding to each of the IPv4 end address and the IPv4 start address of the IPv4 multicast packet (here, the IP multicast routing control information management). Report to means 6). Here, the IPv4 end address (23
8.0.0.1) corresponding to the IPv6 address (ff1
e: 238.0.0.1) and the IPv4 source address (1
An IPv6 address (4 :: 100) corresponding to 33.144.93.2) is reported.

The IP multicast route control information management means 6 performs (process 208) and notifies the IP transmission / reception means 2 of output information (information indicating an interface and a protocol to be output) of the IPv4 multicast packet. Here, the output information of IPv4 output information of all interfaces = OFF, IPv6 output information of interface 11 = ON, and IPv6 output information of other interfaces = OFF is transmitted from the IP multicast route control information management unit 6 to the IP transmission / reception unit 2. Notified.

The IP transmission / reception means 2 performs (processing 209) and sends an IP address to the IPv4 network corresponding to the interface for which IPv4 output information = ON.
Send a v4 multicast packet. Here, since the IPv4 output information of all interfaces is set to OFF, the IPv4 multicast packet is not transmitted to any IPv4 network.

Next, the IP transmission / reception means 2, the IP address conversion information holding means 4 and the IP header conversion means 5 perform (processes 210 to 213) to create an IPv6 multicast packet from the IPv4 multicast packet. The IP transmitting / receiving means 2 performs (Process 214)
In (process 208), an IPv6 multicast packet is transmitted to the IPv6 network corresponding to the interface set to IPv6 output information = ON notified from the IP multicast routing control information management means 6. Here, since the IPv6 output information of the interface 11 is set to ON, the IPv6 multicast packet is transmitted to the IPv6 network 122. Also, IPv6 multicast client 1
04 receives an IPv6 multicast packet from the IPv6 network 122.

As a result, the multicast packets broadcast by the IPv4 multicast server 101 are
6 can be received by the multicast client 104. Next, the IPv6 multicast client 10
4 is an IPv6 multicast group (ff1e :: 2
38.0.0.1) will be described.

The IPv6 multicast client 104
Is ff1e :: 23 according to the MLD protocol.
8. Create an MLD Done message for leaving from the IPv6 multicast group of 0.1.0.1, and send it to the IPv6 network 122. here,
The processing of the conversion device 1 that has received the MLD Done message from the IPv6 network 122 will be described. FIG. 18 is a communication sequence diagram for the process 217.

(Regarding process 217) IP transmitting / receiving means 2
Passes the MLD Done message to the IP multicast membership information management means 7. Upon receiving the MLD Done message, the IP multicast membership information management means 7 receives an MLD Query message for confirming the existence of the IPv6 multicast group subscriber.
A message is created, and the IP transmitting / receiving
The transmission to the v6 network 122 is instructed. The IP transmitting / receiving means 2 transmits the MLD Query message to the IPv6
Send it to the network 122.

If there is another subscriber of the IPv6 multicast group, an MLD Report message indicating that the subscriber has joined the IPv6 multicast group is sent to the network 122 within a predetermined time. The report message is passed to the IP multicast membership information management means 7. In the IP multicast membership information management means 7, the MLD Report and the MLD Done
The message is discarded, and the subsequent processing ends.

If there is no other subscriber of the IPv6 multicast group, the MLD Report indicating that the subscriber has joined the IPv6 multicast group even after a certain period of time has elapsed.
Since the t message is not sent to the IPv6 network 122, the IP multicast membership information management means 7 sends the IP message according to the MLD Done message.
A v6 multicast member information table 62 is created, and information obtained by analyzing the MLD Done message is notified to the IP multicast routing control information management means 6. IP multicast routing information management means 6
Creates the IP multicast route information table 51 according to the information obtained by analyzing the MLD Done message.

Here, by receiving the MLD Done message and a series of subsequent processing, the IPv6 multicast group (ff1e :: 238.0.0.
Since it is determined that the subscriber 1) has disappeared from the IPv6 network 122, the IPv6 address (ff1) in the IPv6 multicast member information table 62 is determined.
e :: 238.0.0.1) is O
FF, IP of the IP multicast route information table 51
The interface 11 of the v6 address (ff1e :: 238.0.0.1) is set to OFF. Also, the IP multicast route information table 51 includes
Depending on the value of the P multicast server address,
IPv6 address (ff1e :: 238.0.0.1)
In some cases, the interface 11 of the corresponding entry is set to OFF.

Next, after (processing 217), the IPv4 multicast server 101
IPv4 multicast packet (23
The process performed by the conversion device 1 that has received the address “8.0.0.1” will be described. However, the processing of the conversion device 1 after the processing 217 repeats the above-described processing 205 to 214 again. Details will be described below.

The IP transmitting / receiving means 2 performs (Step 205) and relays the IPv4 multicast packet
(v4 output information and IPv6 output information) to the IP multicast routing information management means 6. The IP multicast routing control information management means 6 (process 20)
6) is performed, and the IPv6 address corresponding to each of the IPv4 end address and the IPv4 start address is set to the IP address.
An inquiry is made to the address conversion information holding means 4.

The IP address conversion information holding means 4 performs (process 207) to inquire the IPv6 address corresponding to each of the IPv4 end address and the IPv4 start address of the IPv4 multicast packet (here, the IP multicast routing control information management). Report to means 6). Here, the IPv4 end address (23
8.0.0.1) corresponding to the IPv6 address (ff1
e: 238.0.0.1) and an IPv6 address (4 :: 100) corresponding to the IPv4 source address (133.144.93.2) are reported.

The IP multicast route control information management means 6 performs (process 208) to notify the IP transmission / reception means 2 of output information of the IPv4 multicast packet (information indicating an interface and a protocol to be output). Here, the output information of IPv4 output information of all interfaces = OFF and IPv6 output information of all interfaces = OFF is notified from the IP multicast route control information managing means 6 to the IP transmitting / receiving means 2.

The IP transmission / reception means 2 performs (Process 209) and sends an IP address to the IPv4 network corresponding to the interface for which IPv4 output information = ON.
Send a v4 multicast packet. Here, since the IPv4 output information of all interfaces is set to OFF, the IPv4 multicast packet is not transmitted to any IPv4 network.

Next, the IP transmission / reception means 2, the IP address conversion information holding means 4 and the IP header conversion means 5 perform (processes 210 to 213) to create an IPv6 multicast packet from the IPv4 multicast packet.

The IP transmitting / receiving means 2 performs (processing 214), and in (processing 208), the IPv6 network corresponding to the interface whose IPv6 output information notified from the IP multicast routing information management means 6 is set to ON. Sends an IPv6 multicast packet to the server. Here, IPv6 of all interfaces is used.
Since the output information is set to OFF, the IPv6 multicast packet is not sent to any IPv6 network.

(Second Embodiment) FIG. 11 shows a communication network system 2 using a conversion device 1 according to the present invention.
FIG. This communication network system 2
00 is, for example, the conversion device 1 (IPv4 address; 13
3.144.97.1 and 133.144.98.1,
IPv6 addresses 111, 11 via IPv6 addresses; 7 :: 1 and 8 :: 1).
2 and the IPv6 networks 121 and 122 are connected, and furthermore, the IPv4 multicast routers 105 and 1 are connected.
06 and the IPv6 multicast routers 107 and 108 and the IPv4 networks 113 and 114 and the
v6 networks 123 and 124 are connected,
In the IPv4 network 113, an IPv4 multicast server 101 (IPv4 address; 133.144.93.
2), and the IPv4 network 114 includes
IPv4 multicast client 102 (IPv4 address; 1) that receives a multicast packet in v4
33.144.95.2), and the IPv6 network 123 includes an IPv6 multicast server 103 (IPv4) that broadcasts multicast packets in IPv6.
IPv6 network 124 includes an IPv6 multicast client 104 (I) that receives an IPv6 multicast packet.
Pv6 address; 2 :: 2).

The IPv4 multicast server 10
1 sends an IPv4 multicast packet (IPv4 address; 238.0.0.
Broadcast 1), IPv6 multicast server 103
Sends an IPv6 multicast packet (IPv6 address; ff1e :: 23) to the IPv6 network 123.
8.0.0.2) is being broadcast.

Next, the communication network system 2
At 00, the IPv4 multicast server 101
Sends the IPv4 multicast packet (IPv4 address; 238.0.0.1) to the IPv4 network 1
13 and broadcast this IPv4 multicast packet to the IPv6 multicast client 104.
Will be described. However, portions that overlap with the communication network system 100 according to the first embodiment will be omitted to the extent that the description is not redundant.

First, the processing (processing 201 to 204) that the conversion device 1 performs periodically according to the IGMP protocol, the MLD protocol, and the PIM-DM protocol will be described. The IP multicast membership information management means 7 performs (Process 201) to create the IPv4 multicast member information table 61. However, here, since there is no IPv4 multicast group subscriber, no IGMP Report message is received. IP multicast membership information management means 7
Performs (Process 202) to create the IPv6 multicast member information table 62. However, here, since there is no IPv6 multicast group subscriber, no MLD Report message is received.

The IP multicast routing control information management means 6 performs (Process 203) to create the IPv4 adjacent router information table 71. Here, Hello received from the IPv4 multicast routers 105 and 106 is used.
An IPv4 neighbor router information table 71 is created based on the information of the message. The IP multicast routing control information management means 6 performs (process 204) and executes
An adjacent router information table 72 is created. Here, I
The IPv6 neighbor router information table 72 is created based on the information of the Hello message received from the Pv6 multicast routers 107 and 108.

Next, the IPv6 multicast client 104 sets the IPv6 multicast group (ff1
e :: 238.0.0.1) will be described. First, the IPv4 multicast server 1
01 is an IPv4 address for the IPv4 network 113.
A multicast packet (to 238.0.0.1) is transmitted. The IPv4 multicast router 105 uses the IP
v4 multicast packet to IPv4 network 1
Relay to 11.

Here, the processing in the converter 1 that has received the IPv4 multicast packet will be described.
The IP transmitting / receiving means 2 performs (Process 205) and
The relay destination of the four multicast packets (IPv4 output information and IPv6 output information) is inquired to the IP multicast routing control information management means 6. The IP multicast routing control information management means 6 performs (Process 206)
An inquiry is made to the IP address conversion information holding unit 4 for an IPv6 address corresponding to each of the IPv4 end address and the IPv4 start address.

The IP address conversion information holding means 4 performs (processing 207) to determine the IPv6 address corresponding to each of the IPv4 end address and the IPv4 start address of the IPv4 multicast packet from the inquiry source (here, the IP multicast routing control). Information management means 6)
Report to Here, it corresponds to the IPv6 address (ff1e: 238.0.0.1) corresponding to the IPv4 end address (238.0.0.1) and the IPv4 start address (133.144.93.2). IPv
6 addresses (4 :: 100) are reported.

The IP multicast route control information management means 6 performs (processing 208) and notifies the IP transmission / reception means 2 of output information (information indicating an interface and a protocol to be output) of the IPv4 multicast packet.
Here, the output information in which the IPv4 output information of the interface 9 is ON and the IPv6 output information of the interfaces 10 and 11 is ON is notified from the IP multicast route control information managing means 6 to the IP transmitting / receiving means 2.

The IP transmission / reception means 2 performs (Process 209) and sends an IP address to the IPv4 network corresponding to the interface whose IPv4 output information = ON.
Send a v4 multicast packet. Here, since the IPv4 output information of the interface 9 is set to ON, the IPv4 multicast packet is
sent to the v4 network 112.

The IPv4 multicast router 106
IPv4 relayed to IPv4 network 112
The multicast packet is received, but since there is no subscriber of the IPv4 multicast group in the IPv4 network 102, the IPv4 multicast packet is
Discard without relaying to the IPv4 network 102.

Next, the IP transmitting / receiving means 2, the IP address conversion information holding means 4 and the IP header conversion means 5 perform (processes 210 to 213) to create an IPv6 multicast packet from the IPv4 multicast packet.

The IP transmitting / receiving means 2 performs (Process 214), and in (Process 208) the IPv6 output information notified from the IP multicast routing control information managing means 6 to the IPv6 network corresponding to the interface set to ON. To send an IPv6 multicast packet. Here, the IPv6 of the interfaces 10 and 11
6 output information = ON, the IPv6 multicast packet is sent to the IPv6 network 12
1, 122.

[0097] The IPv6 multicast router 107
IPv6 relayed to IPv6 network 121
The multicast packet is received, but since there is no subscriber of the IPv6 multicast group in the IPv6 network 123, the IPv6 multicast packet is
Discard without relaying to the IPv6 network 123.

Similarly, the IPv6 multicast router 108 receives the IPv6 multicast packet relayed to the IPv6 network 122,
Since there is no subscriber of the IPv6 multicast group in the IPv6 network 124, the IPv6 multicast packet is discarded without being relayed to the IPv6 network 124.

Next, a PI requesting that the relay of the IPv6 multicast packet (ff1e :: 238.0.0.1) to the IPv6 network 122 be stopped.
The processing of the conversion device 1 that has received the M-Prune message from the IPv6 multicast router 108 will be described. FIG. 19 is a communication sequence diagram for the processes 231 to 233.

(Regarding the process 231) IP transmitting / receiving means 2
Passes the PIM-Prune message to the IP multicast routing information management means 6. The IP multicast routing control information management means 6 uses the PIM-Prune message to request the IPv6 multicast address and
An inquiry is made to the IP address conversion information holding means 4 for an IPv4 address corresponding to each of the Pv6 multicast server addresses.

(Regarding the process 232) First, the IP address conversion information holding unit 4 sends the IPv6
IPv6 multicast address (ff1e :: 238.0.0.1) requested not to relay to
It checks whether it is registered in the P address conversion table 41 and reports to the inquiry source (here, the IP multicast route control information management means 6) whether the corresponding IPv4 address is registered or unregistered. If not registered, an IPv6 multicast address and an IPv4 address (238.0.0.
1) are registered in the IP address conversion table 41 in association with 1), and this IPv4 address is reported.

Next, the IP address conversion information holding means 4
Checks whether the IPv6 multicast server address (4 :: 100) requested not to be relayed to the IPv6 network 122 is registered in the IP address conversion table 41, and the corresponding IPv4 address is registered or unregistered. Is reported to the inquiry source (here, the IP multicast routing information management means 6). If the IPv4 unicast address has not been registered, the IPv4 unicast address is obtained from the conversion IP address holding unit 3, registered in the IP address conversion table 41 in association with the IPv6 multicast server address, and then the IPv4 unicast address is reported. Here, the IPv6 multicast server address (4 :: 100) is the IP address of the multicast server.
Since the IP address is registered in the IP address conversion table 41 in association with the v4 address (133.144.93.2), the IPv4 address of (133.144.93.2) is reported.

(Regarding the process 233) The IP multicast routing control information management means 6 checks the corresponding IPv6 multicast address (ff1e :: 238.0.0.1) in the IP multicast routing information table 51 and the corresponding IPv6 multicast server address. '4 :: 1
00 'and set the IPv6 output of the interface that has received the PIM-Prune message to OFF, and furthermore, the I corresponding to the corresponding IPv6 multicast address (ff1e :: 238.0.0.1)
Pv4 address (238.0.0.1) and corresponding IPv6 multicast server address (4 :: 10)
0) corresponding to the IPv4 address (133.144.9).
3.2), and set the IPv6 output of the interface that has received the PIM-Prune message to OFF. Note that here, the IPv4 address corresponding to the IPv6 multicast address 'ff1e :: 238.0.0.1' is '238.0.0.1', and
IPv6 multicast server address' 4 :: 10
If the IPv4 address corresponding to '0'is' 133.144.
The IPv6 output of the interface 11 which is 93.2 'is set to OFF. FIG.
4 is a communication sequence diagram for No. 4. FIG.

(Regarding Process 234) The IP multicast routing control information management means 6 performs (Process 233) the IPv4 output of all interfaces = OFF, and
When there is a route in which the IPv6 output of all interfaces is OFF, PIM-Pr requests not to relay the IP multicast packet of the route.
Une message is created, and IP transmitting / receiving means 2
To the corresponding network. The IP transmitting / receiving means 2 outputs a PIM-Prune message to the specified network.

Here, according to (Process 233), IPv4 output of all interfaces is OFF, and
Since there is no path in which the IPv6 output of all interfaces has been turned OFF, the PIM-Prune message is not transmitted. Also, an IPv6 multicast packet (ff
1e :: 238.0.0.1) to the IPv6 network 121
Une message is sent to IPv6 multicast router 1
07, or a PIM requesting to stop relaying an IPv4 multicast packet (addressed to 238.0.0.1) to the IPv4 network 112.
When the conversion device 1 receives the Prune message from the IPv4 multicast router 106, the conversion device 1
31 to 234), but at this time, by (processing 233), the IP multicast address (23
8.0.0.1), the IPv4 output and IPv6 output of all the interfaces that are the IP multicast server address (133.144.93.2) are turned off, and the IP multicast packet on the route is not relayed. A PIM-Prune message is created, and an upstream router (for example, the next hop router of the IP multicast server address, here, the IPv4 multicast router 105) of the path is present. Send it to the IPv4 network 111.

[0106] The PIM-Prune message is an IPv4 message.
4 received by the multicast router 105, and
4 multicast router 105 determines that the corresponding IPv4 multicast address is (238.0.0.1) and
The corresponding IPv4 multicast server address (13
3.144.93.2) is not relayed to the IPv4 network 111.

Next, the IPv6 multicast client 104 sets the IPv6 multicast group (ff1
e :: 238.0.0.1) will be described. The IPv6 multicast client 104
According to the MLD protocol, an MLD Report message for joining an IPv6 multicast group (ff1e :: 238.0.0.1) is created and transmitted to the network 124. When receiving the MLD Report message from the network 124, the IPv6 multicast router 108 receives the MLD Report message from the network 124, and according to the MLD protocol and the PIM-DM protocol, the IPv6 multicast packet (ff1e :: 238.0.0.1).
Create a PIM Graph message requesting that the packet be forwarded to the IPv6 network 124, and
Send it to the Pv6 network 122.

Here, the processing of the conversion device 1 that has received the PIM Graph message from the IPv6 network 122 will be described. FIG. 21 shows processes 235-2.
37 is a communication sequence diagram for 37. FIG.

(Regarding process 235) IP transmitting / receiving means 2
Passes the PIM Graph message to the IP multicast routing control information management means 6. The IP multicast routing control information management means 6 transmits the IP multicast server address and the IPv6 multicast address which are requested to be relayed to the IPv6 network 122 in the PIM Graph message.
The IP address conversion information holding means 4 is inquired about the v4 address.

(Regarding the process 236) First, the IP address conversion information holding means 4 sends the IPv6
IPv6 multicast address (ff1e :: 238.0.0.1) requested to be relayed to
Check whether it is registered in the address conversion table 41,
It reports to the inquiry source (here, the IP multicast routing information management means 6) whether the corresponding IPv4 address is registered or unregistered. If not registered, IPv6
The IP address conversion table 41 associates a multicast address with an IPv4 address (238.0.0.1) obtained by deleting fixed data (IPv6 multicast prefix, for example, ff1e :: / 96) from the IPv6 multicast address. Register for IPv4
Report the address.

Next, the IP address conversion information holding means 4
Checks whether the IPv6 multicast server address (4 :: 100) requested to be relayed to the IPv6 network 122 is registered in the IP address conversion table 41, and inquires the corresponding IPv4 address from the inquiry source (here, IP This is reported to the multicast route control information management means 6). If not registered, an IPv4 unicast address is acquired from the conversion IP address holding unit 3, registered in the IP address conversion table 41 in association with the IPv6 multicast server address, and then the IPv4 unicast address is reported. Here, the IPv6 multicast server address (4 :: 100) is replaced with the IPv4 address (133.14).
4.93.2) and registered in the IP address conversion table 41, so that the IPv4 address (1
33.144.93.2) will be reported.

(Regarding the process 237) The IP multicast route control information management means 6 uses the corresponding IPv6 multicast address (ff1e :: 238.0.0.1) in the IP multicast route information table 51 and the corresponding IPv6 multicast server. Address (4 ::
100), and sets the IPv6 output of the interface that has received the PIM Graph message to ON, and further sets the I corresponding to the corresponding IPv6 multicast address (ff1e :: 238.0.0.1).
Pv4 address (238.0.0.1) and the corresponding IPv6 multicast server address (4 :: 10
0) corresponding to the IPv4 address (133.144.9).
3.2), and set the IPv6 output of the interface that has received the PIM Graph message to ON.

Here, the IP address corresponding to the IPv6 multicast address 'ff1e :: 238.0.0.1' is used.
The IPv6 output of the interface 11 whose IPv4 address is "133.144.93.2" corresponding to the IPv4 address "238.0.0.1" and the IPv6 multicast server address "4 :: 100" is set to ON. Will be. FIG. 22 is a communication sequence diagram for the process 238.

(Regarding the process 238) The IP multicast routing control information management means 6 performs (the process 237) the IPv4 output = ON or the IPv6 output = O
If there is a route that has become N, a PIM Gr requesting that the IP multicast packet of the route be relayed
aft message and the IP transmitting / receiving means 2
To the corresponding network. The IP transmitting / receiving means 2 outputs the PIM Graph message to the specified network.

Here, by the (process 237), the corresponding IPv6 multicast address (ff1e :: 2
38.0.0.1) (23)
8.0.0.1) and the IPv6 multicast server address (4 :: 100) corresponding to the IPv6
Since the IPv6 output of the interface 11, which is the IP address 4 (133.144.93.2), is set to ON, the IPv4 multicast address becomes, for example, '23.
8.0.0.1 ', a PIM Graph message for requesting to relay an IPv4 multicast packet with an IPv4 multicast server address of' 133.144.93.2 'to the IPv4 network 111 is created, and the PIM Graph message is created. The message is sent to the IPv4 network 111 in which the upstream router of the route (for example, the next hop router of the IP multicast server address, here, the IPv4 multicast router 105) is located.

The PIM Graph message is composed of the IPv
4 received by the multicast router 105, and
4 multicast router 105, if the IPv4 multicast address is, for example, “238.0.0.1”,
v4 multicast server address is' 133.14
The 4.93.2 'IPv4 multicast packet is relayed to the IPv4 network 111.

Next, the IPv6 multicast client 104 sets the IPv6 multicast group (ff1
e :: 238.0.0.1) will be described. IPv6 multicast client 104
Is ff1e :: 23 according to the MLD protocol.
8. Create an MLD Done message for leaving from the IPv6 multicast group of 0.1.0.1, and send it to the IPv6 network 124. When receiving the MLD Done message from the network 124, the IPv6 multicast router 108 receives the MLD Done message according to the MLD protocol and the PIM-DM protocol.
6 multicast packets (ff1e :: 238.0.
A PIM-Prune message requesting not to relay the PIM-0.1 to the IPv6 network 124 is sent to the IPv6 network 122.

When the conversion device 1 receives the PIM-Prune message from the IPv6 network 122,
(Processes 231 to 234) to stop the relay of the route and to request the stop of the relay of the route.
Ne message is created, and this PIM-Prune message is sent to the upstream router of the route (here, the IPv4 multicast router 105). Thereby, the IPv4
4 The multicast router 105 thereafter sets the route I
The Pv4 multicast packet is not relayed to the IPv4 network 111.

In the first and second embodiments described above, the IPv4 multicast server 101 is
IPv4 broadcasting at 4 address '238.0.0.1'
The case where the multicast packet is received by the IPv6 multicast client 104 has been described.
IPv6 broadcast by the Pv6 multicast server 103 with an IPv6 address (ff1e :: 238.0.0.2)
The same applies to the case where the IPv4 multicast client 102 receives six multicast packets.

In the first and second embodiments described above, the IP broadcast by the IPv4 multicast server 101
When converting a Pv4 multicast packet to an IPv6 multicast packet, an IPv4 destination address (2
38.0.0.1) with a fixed pattern added to the top
28-bit IPv6 address (for example, ff1e ::
ffff: 238.0.0.1) has been described. For example, in addition to an IPv4 unicast address and an IPv6 unicast address, an IPv4 multicast address and I
The Pv6 multicast address may be held in the conversion IP address holding unit 3 in advance, and may be converted to an IPv6 multicast address (for example, ff1e :: 100) acquired from the conversion IP address holding unit 3.

In the first and second embodiments described above, the conversion device 1 reflects the IPv4 multicast route control information obtained by exchanging with the adjacent IPv4 multicast router on the IPv6 multicast route control information. By exchanging with an adjacent IPv6 multicast router, the IPv6 multicast server 10
3 broadcasts the IP multicast packet to IPv4
Relay to the multicast client 102,
IPv6 multicast routing control information obtained by exchanging with an adjacent IPv6 multicast router is transmitted to IPv4
After being reflected in the multicast routing information,
By exchanging with a Pv4 multicast router,
The case where the IP multicast packet broadcast by the IPv4 multicast server 101 is relayed to the IPv6 multicast client 104 has been described.
An administrator sets IPv6 multicast path control information necessary for relaying an IP multicast packet broadcasted by the Pv6 multicast server 103 to the IPv4 multicast client 102 in the conversion apparatus 1, or the IPv4 multicast server 101 broadcasts. I required to relay an IP multicast packet to the IPv6 multicast client 104
The same applies to the case where the administrator sets the Pv4 multicast path control information in the converter 1.

The IP address conversion information holding means 4
Deletes the association between the held IPv4 address and the IPv6 address that has not been referenced for a certain period of time, and deletes the deleted IPv4 unicast address or IPv6 address.
The unicast address may be returned to the conversion IP address holding unit 3.

[0123]

According to the present invention, as described above, I
An IP multicast packet broadcast from an IPv6 terminal can be received by an IPv6 terminal, and an IP multicast packet broadcast from an IPv6 terminal can be received by an IPv6 terminal.
It can be received by an IPv4 terminal.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of a conversion device 1 according to the present invention.

FIG. 2 is a configuration diagram of an IPv4 unicast address table 31;

FIG. 3 is a configuration diagram of an IPv6 unicast address table 32;

FIG. 4 is a configuration diagram of an IP address conversion table 41.

FIG. 5 is a configuration diagram of an IP multicast route information table 51;

FIG. 6 is a configuration diagram of an IPv4 adjacent router information table 71.

FIG. 7 is a configuration diagram of an IPv6 adjacent router information table 72;

FIG. 8 is an IPv4 multicast member information table 6
FIG.

FIG. 9 is an IPv6 multicast member information table 6
FIG.

FIG. 10 is a configuration diagram of a communication network system 100 using a conversion device 1 according to the present invention.

FIG. 11 is a configuration diagram of a communication network system 200 using the conversion device 1 according to the present invention.

FIG. 12 is a communication sequence diagram for processing 201 and 202.

FIG. 13 is a communication sequence diagram for processes 203 and 204.

FIG. 14 is a communication sequence diagram for processing 205 to 207.

FIG. 15 is a communication sequence diagram for processing 208 and 209.

FIG. 16 is a communication sequence diagram for processes 210 to 214.

FIG. 17 is a communication sequence diagram for a process 215.

FIG. 18 is a communication sequence diagram for a process 217.

FIG. 19 is a communication sequence diagram for processing 231 to 233.

FIG. 20 is a communication sequence diagram for a process 234.

FIG. 21 is a communication sequence diagram for processing 235 to 237.

FIG. 22 is a communication sequence diagram for a process 238.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conversion device 2 IP transmission / reception means 3 IP address holding means for conversion 4 IP address conversion information holding means 5 IP header conversion means 6 IP multicast membership information management means 7 IP multicast route control information management means 31 IPv4 unicast address table 32 IPv6 Unicast address table 41 IP address conversion table 51 IP multicast route information table 61 IPv4 multicast member information table 62 IPv6 multicast member information table 71 IPv4 adjacent router information table 72 IPv6 adjacent router information table 101 IPv4 multicast server 102 IPv4 multicast client 103 IPv6 multicast Server 104 IPv6 multicast client 1 5,106 IPv4 multicast router 107 and 108 IPv6 multicast router 111 to 114 IPv4 network 121 to 124 IPv6 Network

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shinji Nozaki 1 Horiyamashita, Hadano-shi, Kanagawa Prefecture Hitachi, Ltd. Enterprise Server Division (72) Inventor Motonao Sawada 1 Horiyamashita, Hadano-shi, Kanagawa 1 F-term in the Enterprise Server Division (reference) 5K030 GA04 HA08 HD03 JL07 KA05 KA13 LA08 LB05 LB15 LD05 5K034 AA17 BB06 DD03 EE11 FF06 HH01 HH02 HH61 KK27 LL01 SS02

Claims (10)

[Claims] 1. A multicast communication method between an IPv4 network including an IPv4 terminal and an IPv6 network including an IPv6 terminal, wherein fixed data is added to an IPv4 address of a certain group of an IPv4 multicast packet broadcast by the IPv4 terminal. When a request to join the group with the assigned IPv6 address is received from an IPv6 terminal, the IPv6 address of the group is reflected in management information of an IP multicast group membership protocol, and the IPv6 address of the group and the IPv4 address of the group are reflected. And, as a relay request for the IPv4 address of the group, reflected in the management information of the IP multicast routing protocol, and the IPv4 multicast broadcast by the IPv4 terminal. When the IPv4 multicast packet is received, the IPv4 destination address of the group included in the IPv4 multicast packet is converted into a corresponding IPv6 destination address of the group, and a predetermined IPv6 unicast address is selected. By converting the IPv4 source address contained in the IPv4 source address into the IPv6 source address, an IPv6 multicast packet is created from the IPv4 multicast packet.
A multicast communication method for sending to a v6 network. 2. A multicast communication method between an IPv4 network including an IPv4 terminal and an IPv6 network including an IPv6 terminal, wherein fixed data is deleted from an IPv6 address of a certain group of an IPv6 multicast packet broadcast by the IPv6 terminal. When a request to join the group with the assigned IPv4 address is received from an IPv4 terminal, the IPv4 address of the group is reflected in management information of an IP multicast group membership protocol, and the IPv4 address of the group and the IPv6 address of the group are reflected. Address, and as a relay request for the IPv6 address of the group, reflected in the management information of the IP multicast routing protocol, and the IPv6 multicast broadcast by the IPv6 terminal. When receiving the IPv6 multicast packet, the IPv6 multicast packet converts the IPv6 destination address of the group included in the IPv6 multicast packet into a corresponding IPv4 destination address of the group and selects a predetermined IPv4 unicast address. By converting the IPv6 source address contained in the IPv6 source address into the IPv4 source address, an IPv4 multicast packet is created from the IPv6 multicast packet.
A multicast communication method for sending to a v4 network. 3. An adjacent IPv6 multicast router transmits IP multicast routing control information for requesting relay of a packet of an IPv6 address group formed by adding fixed data to an IPv4 address of an IPv4 multicast packet group broadcasted by the IPv4 terminal. When received via the IPv6 address, the IPv6 address of the group is associated with the IPv4 address of the group, and the request is reflected in the management information of the IP multicast routing protocol as a relay request for the IPv4 address of the group. Item 2. The multicast communication method according to Item 1. 4. An adjacent IPv4 multicast router transmits IP multicast routing control information for requesting relay of a packet of an IPv4 address group obtained by deleting fixed data from an IPv6 address of an IPv6 multicast packet group broadcasted by the IPv6 terminal. When received via the IPv6 address, the IPv4 address of the group is associated with the IPv6 address of the group, and the request is reflected in the management information of the IP multicast routing protocol as a relay request for the IPv6 address of the group. Item 3. A multicast communication method according to Item 2. 5. The method according to claim 1, further comprising exchanging, with an adjacent IPv6 multicast router and / or an IPv4 multicast router, IP multicast routing control information concerning a network to which the broadcasted multicast packet is to be relayed. The multicast communication method according to any one of the above. 6. A multicast communication device in a communication network system provided between an IPv4 network including an IPv4 terminal and an IPv6 network including an IPv6 terminal and including a conversion device for transmitting and receiving an IP packet, comprising: IP transmitting / receiving means for transmitting / receiving, and a conversion I for holding an IP address used for IP header conversion
P address holding means, and I which holds IPv4 and IPv6 addresses in association with each other
P address conversion information holding means, IP header conversion means for performing IPv4 and IPv6 IP header conversion, IP to relay IP multicast packets broadcast from IPv4 and IPv6 IP multicast servers
IP multicast routing control information managing means for mutually converting IP multicast routing control information relating to a network and performing route control; and IP multicast membership information managing means for managing IP multicast members. The IP address conversion information holding unit is inquired of the IPv4 destination address of the IPv4 multicast packet passed from the IP transmitting / receiving unit, and the corresponding IPv6
IP address conversion using an IPv6 address using an IPv6 multicast address, and inquiring the IPv4 start address of the IPv4 multicast packet to the IP address conversion information holding unit, and converting the IPv4 multicast packet into an IPv6 start address using the corresponding IPv6 address. It creates an IPv6 multicast packet from an IPv4 multicast packet, instructs the IP transmitting / receiving means to send the packet to an IPv6 network, and queries the IP address translation information holding means for an IPv6 destination address of the IPv6 multicast packet passed from the IP transmitting / receiving means. To convert the IPv6 destination address of the IPv6 multicast packet to the IPv4 destination address using the corresponding IPv4 address, and to hold the IP address translation information. Contact the means,
A multicast communication apparatus that creates an IPv4 multicast packet from an IPv6 multicast packet by IP header conversion that converts the IPv4 multicast address into an IPv4 start address using a corresponding IPv4 address, and instructs an IP transmitting / receiving unit to send the packet to an IPv4 network. 7. The method according to claim 1, wherein the means for holding the IP address translation information comprises:
IPv4 destination address of 4 multicast packets;
I by adding fixed data to the IPv4 destination address
A Pv6 multicast address, an IPv4 source address of an IPv4 multicast packet,
An IPv6 unicast address obtained from the P address holding means, an IPv6 end address of an IPv6 multicast packet broadcast by an IPv6 terminal of the IPv6 network, an IPv4 multicast address obtained by deleting fixed data from the IPv6 end address,
IPv6 source address of v6 multicast packet and IPv4 obtained from IP address holding means for conversion
7. The multicast communication device according to claim 6, wherein the multicast communication device is configured to store a unicast address in association with the unicast address. 8. An IP multicast route control information management means manages IP multicast route control information in accordance with each of the IPv4 and IPv6 IP multicast route control protocols, and manages the IPv6 multicast packets broadcasted by the IPv6 terminal from the IPv6 address of the group of the IPv6 multicast packet. When receiving, from an adjacent IPv4 multicast router, IP multicast routing control information requesting relay of a packet of an IPv4 address group formed by deleting fixed data, fixed data is added to the IPv4 address and the IPv4 address of the IPv4 multicast group. The IP address conversion information holding means is instructed to register an IPv6 address that can be obtained and registered, and an IP multicast is sent as a relay request to the IPv6 address of the group. Reflected in the management information of the routing protocol,
IP multicast for exchanging IP multicast routing information with an adjacent IPv6 multicast router, and requesting a relay of a packet of a group of IPv6 addresses that can be obtained by adding fixed data to an IPv4 address of a group of IPv4 multicast packets broadcast by the IPv4 terminal. When the route control information is received from an adjacent IPv6 multicast router, the IPv6 address of the IPv6 multicast group and the IPv4 address obtained by deleting the fixed data from the IPv6 address are instructed and registered in the IP address conversion information holding means, The request is reflected in the management information of the IP multicast routing protocol as a relay request for the IPv4 address of the
8. The multicast communication device according to claim 6, wherein IP multicast routing control information is exchanged with a multicast router. 9. An IPv4 multicast membership information management unit manages members of an IPv4 multicast group according to an IPv4 IP multicast group membership protocol, and manages members of an IPv4 multicast group transmitted from an IPv4 terminal in an IPv4 network to be connected. When receiving the join request, the IPv4 address of the IPv4 multicast group and the IPv6 address that can be obtained by adding fixed data to the IPv4 address are reflected in the management information of the IP multicast group membership protocol, and the IP address conversion information holding means is received. Instruct and register
Instruct the IP multicast routing control information management means to register the IP multicast routing control information requesting the relay of the packet of the IPv6 address, register the IP multicast routing control information, and manage the members of the IPv6 multicast group in accordance with the IPv6 IP multicast group membership protocol, and connect. When a request to join an IPv6 multicast group transmitted from an IPv6 terminal in an IPv6 network is received, the request is reflected in the management information of the IP multicast group membership protocol, and the IPv6 address of the IPv6 multicast group and fixed data from the IPv6 address. And the IPv4 address created by deleting
Instructs the address translation information holding means to register, and requests the relay of the packet of the IPv4 address.
9. The multicast communication device according to claim 6, wherein said multicast routing control information is instructed to be registered by an IP multicast routing control information managing means. 10. The IP address conversion information holding means,
IPv4 unicast address and IPv6 held
10. The multicast communication device according to claim 6, wherein a unicast address that has not been referred to for a predetermined time is deleted and returned to the conversion IP address holding unit.